The problem was resolved by replacing the spark plug wires and a coil. The technician said it was not an obvious one considering how the symptoms manifested. It was a stroke of good luck it decided to stumble and keep playing up while he was looking at it. Case closed.

For the helpful and curious, best guess is it is not the fuel system as no fuel anomalies can be found. Maybe an errant sensor that is putting the engine into a limp home mode, but would expect an error code from that.

The replacement pump was not OEM. It was replaced because of vapour lock in very hot weather (above 38C). The current symptoms are much different. What started out to appear random might be starting to converge. Thanks for the pressure info. Will be worth a look if the 2.0 non-turbo is configured th...

Thanks for that :) In Australia the fuel drying additives common in the US do not seem to exist so E10 seemed a reasonable approach to address possible moisture. We normally would not be using it. My understanding is E10 essentially atomises moisture so it does not affect running as it goes through ...

It is increasingly looking like something in the fuel tank could be interfering with the fuel pickup. Is the fuel pump inside the tank and if so does it mount through the top so it can be removed from the boot/trunk?

Recently the vehicle (2.0 automatic) started exhibiting random loss of power and missing that would be symptomatic of bad fuel or water in the fuel. The servicing shop checked the fuel system and found nothing amiss, and there are no error codes. We have tried E10 in case it was moisture in the fuel...